Heretofore, usual cells of this type comprise basically cylindrical vessels having a removable base which is designed as or forms a filter holder. The base is imperviously connected to the liquid-feeding vessel by means of a gasket or some form of circumferential seal, usually under suitable pre-stress. In such devices, the available filtration surface corresponds practically to the radial cross section of the pressure filtration cell. In order to achieve optimum filtration, special balanced relationships are coordinated and established between the filtration surface, the volume of liquid, i.e., the height of the cylindrical feeding vessel, and the maximum operational pressure. However, such coordination completely disregards both the purpose of the filtration to be carried out, as well as the nature and concentration of the liquid which is to be filtered.
For two completely identical media that are to be filtered, a smaller filtering surface will be selected if the residue is to be processed, and a larger filtering surface will be selected, if the filtrate alone is to be processed. Similarly, if the residue is to be collected, analyzed, and/or processed for two otherwise identical solutions, a larger filtering surface will be selected for a more concentrated solution, while a smaller filtering surface will be selected for a more dilute solution. The usual pressure filtration cells cannot fundamentally do justice to these demands, since their filtration surfaces are essentially always equal to the radial cross section of the feeding vessels. After these facts have been established, the only remaining variable is the height of the feeding vessel. When there is a great volume to be filtered, this forces one either to use unwieldy high vessels or to fill up the pressure filtration cell more frequently, which as a rule results in cumbersome handling.
In view of this existing state of technological development, it is the aim of the invention to create a pressure filtration cell in which the filtering surface is independent of the dimensions of the cell.